Trend is more evident in men and may be due to ultraviolet exposure while driving

Friday, December 10, 2010 (Last Updated: 12/13/2010)

FRIDAY, Dec. 10 (HealthDay News) -- There is an increased prevalence of left-sided skin cancers compared with right-sided skin cancers, especially in men and particularly with malignant melanoma in situ, according to research published in the December issue of the Journal of the American Academy of Dermatology.

Susan T. Butler, M.D., and Scott W. Fosko, M.D., of Saint Louis University, conducted a retrospective review of 1,047 patients with skin cancer, 890 of whom had non-midline cancers, who had been referred to their Mohs micrographic surgery and cutaneous oncology unit in 2004.

When the researchers included all types of skin cancers, more cancers occurred on the left (52.6 percent) than the right (47.4 percent) (P = .059). When they divided by sex, they found that there were significantly more skin cancers on the left (301) than on the right (256) in male patients only (P = .042). The left-sided predominance was even more pronounced when analyzing cancers of the head and neck only, sites that are most directly exposed to ultraviolet light when driving. When the authors included only malignant melanoma in situ, they found significantly more left-sided cancers (31/42, 74 percent) than right (11/42, 26 percent).

"The existence of a left-sided trend in both nonmelanoma skin cancer and noninvasive melanomas underlines the importance of minimizing sun exposure while in the car. This can be achieved by laminating or tinting window glass," the authors write.